Abstract |
To see whether kinetic assays of lipoamide dehydrogenase could be used for carrier detection or preclinical diagnosis, Michaelis-Menten constants (KmL and KmH) for the enzyme were determined in platelets from families with a form of recessive Friedreich ataxia and low activities of the enzyme. The KmL of patients' enzyme was 132 +/- 5 microM lipoamide (mean +/- SEM) versus 56 +/- 9 microM for controls (p less than 0.001), and KmH for the patients was 421 +/- 19 microM versus 147 +/- 14 microM for the controls (p less than 0.001). The activity and Km values of one patient's enzyme were abnormal 1 year before neurologic signs appeared. The Km values for the enzymes of the six parents were also elevated (average KmL, 105 +/- 10 microM; average KmH, 378 +/- 47 microM, p less than 0.02). The maximal activities of the parents' enzymes, relative to a mitochondrial marker, were intermediate between the mean maximal control activity and the mean activity for the affected offspring. The data suggest that the abnormalities of lipoamide dehydrogenase are inherited in a recessive pattern in these families.
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Authors | R A Kark, M Rodriguez-Budelli, S Perlman, W F Gulley, K Torok |
Journal | Neurology
(Neurology)
Vol. 30
Issue 5
Pg. 502-8
(May 1980)
ISSN: 0028-3878 [Print] United States |
PMID | 6892725
(Publication Type: Case Reports, Journal Article, Research Support, U.S. Gov't, P.H.S.)
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Chemical References |
- Dihydrolipoamide Dehydrogenase
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Topics |
- Adolescent
- Adult
- Blood Platelets
(enzymology)
- Child
- Dihydrolipoamide Dehydrogenase
(deficiency, genetics)
- Female
- Friedreich Ataxia
(diagnosis, enzymology, genetics)
- Genes, Recessive
- Genetic Carrier Screening
- Humans
- Kinetics
- Male
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